Mine warfare has always been an effective tool for protecting friendly harbors or neutralizing enemy harbors. In the Revolutionary War a colonist named Bushnell fitted some powder kegs with a gun lock and hammer exploders and used them as contact mines to destroy British river traffic. By the time of World War I mines had become quite sophisticated and became essential in many military operations. During that war the allies bottled up the German U-boats in the North Sea by laying an enormous barrage of mines between Norway and Scotland so that the allies could use their Atlantic shipping routes with reasonable safety. By WWII many varied systems of mines were utilized and numerous mine laying vessels were involved in laying extensive fields of controlled and uncontrolled mines. The most recent use of mines was in the mining of Hypong Harbor. This operation demonstrated that mine warfare is still an excellent weapon system and one of the most cost effective in existence. In all of these operations, however, it has been very difficult to plant these mines covertly, especially when the mines are planted as an offensive weapon in an enemy harbor or other designated area. The presence of a mine laying ship obviously gives away the presence of the mine laying operation. In recent history most of the mine laying ships have been scrapped and mine laying is now accomplished by aircraft. Mine laying from aircraft has the same problem as mine laying from surface ships, namely giving away the location of the operation.
Submarines have the capability of laying mines. However, in order to lay mines the submarine must sacrifice its complement of torpedoes. In addition, the newer class submarines are not safe in the shallow waters next to harbors where mines are most effective. These are two very important factors not desirable to submarine commanders. If mines are to be deployed clandestinely a system is needed that would not jeopardize the submarines' present weapon system and yet would provide a safe standoff position for effective, clandestine mine planting.